CGCampbell has provided a good answer. It is likely that you will not be granted a Schengen visa (that is what you are applying for, there's no Swedish visa) because your situation is precisely the one where governments often deny visas - you are from a less developed country, cannot show a source of income, and cannot show strong ties to your home country.
If you are traveling to Sweden on a visa, you are generally required to show at least 450 SEK (about 60 USD) for each day you will be staying in the country. That from the Swedish Migration Board. It also says it's possible to travel with a lower amount of money if someone will be providing for your needs.
There is one possibility for you, which is that your boyfriend completes and provides an invitation to Sweden on your behalf. It's described on this page, still in Swedish, but you can see the form. Scroll down to where it says Blanketter, and the second link shows the invitation form in English. Here's the page in English, it says the same thing as in Swedish. The procedure is such: the person in Sweden (your boyfriend) completes the form and sends it along with the necessary documentation to you. You then enclose all of that with your visa application at the Swedish consulate or embassy.
In the case of an invitation, your boyfriend would be required to guarantee that he is paying for your stay, and also show sufficient income. His legal status in Sweden, which you have not provided in your question, is critical here. If he's not a resident of Sweden, it will essentially be impossible for him to send an invitation (it doesn't say so directly anywhere, but the form requires a personal identity number, which only residents have, and it wouldn't be possible to get the other required documents from the tax agency without being a resident). If he is a resident of Sweden, and provably has enough money (which means he has a job or can show a bank statement with a fairly significant sum of money), then it might help you.
If your boyfriend cannot provide such an invitation for financial or residency reasons, it is extremely unlikely you would be granted a visa from a repeat application or appeal. If such an invitation can be provided, it still does not guarantee you a visa because there is no strong proof, given what you described, of you intending to leave the Schengen area.